Signal injection at radio tap points in a time domain

ABSTRACT

A system can comprise a radio unit comprising a digital front end, wherein the digital front end comprises a group of tap points that are configured to receive a first custom signal. The system can also comprise a first component that is configured to originate the first custom signal. The system can also comprise a second component that is configured to select a first tap point of the group of tap points, and inject the first custom signal into the first tap point.

BACKGROUND

A radio can comprise a receiver and a transmitter that are used toreceive and transmit, respectively, data.

SUMMARY

The following presents a simplified summary of the disclosed subjectmatter in order to provide a basic understanding of some of the variousembodiments. This summary is not an extensive overview of the variousembodiments. It is intended neither to identify key or critical elementsof the various embodiments nor to delineate the scope of the variousembodiments. Its sole purpose is to present some concepts of thedisclosure in a streamlined form as a prelude to the more detaileddescription that is presented later.

An example system can operate as follows. The system can comprise aradio unit comprising a digital front end, wherein the digital front endcomprises a group of tap points that are configured to receive a firstcustom signal. The system can also comprise a first component that isconfigured to originate the first custom signal. The system can alsocomprise a second component that is configured to select a first tappoint of the group of tap points, and inject the first custom signalinto the first tap point.

An example method can comprise identifying, by a system comprising aprocessor, a group of tap points in a digital front end of a radio unit,wherein the group of tap points are configured to receive a first customsignal. The method can further comprise originating, by the system, thefirst custom signal. The method can further comprise selecting, by thesystem, a first tap point from the group of tap points. The method canfurther comprise injecting, by the system, the first custom signal intothe first tap point.

An example apparatus can comprise a first component that is configuredto originate a first custom signal. The apparatus can further comprise asecond component that is configured to select a first tap point of agroup of tap points of a digital front end of a radio unit. Theapparatus can further comprise a third component that is configured toinject the first custom signal into the first tap point.

BRIEF DESCRIPTION OF THE DRAWINGS

Numerous embodiments, objects, and advantages of the present embodimentswill be apparent upon consideration of the following detaileddescription, taken in conjunction with the accompanying drawings, inwhich like reference characters refer to like parts throughout, and inwhich:

FIG. 1 illustrates an example system architecture for injecting a signalinto a radio down link chain, and that can facilitate signal injectionat radio tap points in a time domain, in accordance with an embodimentof this disclosure;

FIGS. 2A and 2B illustrate another example system architecture forinjecting a signal into a radio down link chain, and that can facilitatesignal injection at radio tap points in a time domain, in accordancewith an embodiment of this disclosure;

FIGS. 3A and 3B illustrate an example system architecture for injectinga signal into a radio up link chain, and that can facilitate signalinjection at radio tap points in a time domain, in accordance with anembodiment of this disclosure;

FIGS. 4A and 4B illustrate an example system architecture for a radiounit, and that can facilitate signal injection at radio tap points in atime domain, in accordance with an embodiment of this disclosure;

FIGS. 5A, 5B, 5C, and 5D illustrate illustrates an example systemarchitecture for a radio system, and that can facilitate signalinjection at radio tap points in a time domain, in accordance with anembodiment of this disclosure;

FIG. 6 illustrates an example system architecture that can facilitatesignal injection at radio tap points in a time domain, in accordancewith an embodiment of this disclosure;

FIG. 7 illustrates another example system architecture that canfacilitate signal injection at radio tap points in a time domain, inaccordance with an embodiment of this disclosure;

FIG. 8 illustrates another example system architecture that canfacilitate signal injection at radio tap points in a time domain, inaccordance with an embodiment of this disclosure;

FIG. 9 illustrates another example system architecture that canfacilitate signal injection at radio tap points in a time domain, inaccordance with an embodiment of this disclosure;

FIG. 10 illustrates another example system architecture that canfacilitate signal injection at radio tap points in a time domain, inaccordance with an embodiment of this disclosure;

FIG. 11 illustrates another example system architecture that canfacilitate signal injection at radio tap points in a time domain, inaccordance with an embodiment of this disclosure;

FIG. 12 illustrates another example system architecture that canfacilitate signal injection at radio tap points in a time domain, inaccordance with an embodiment of this disclosure.

FIG. 13 illustrates an example process flow that can facilitate signalinjection at radio tap points in a time domain, in accordance with anembodiment of this disclosure.

DETAILED DESCRIPTION Overview

In modern wireless communications deployments, aspects and impacts ofradio development engineering and system design tradeoffs can havefar-reaching implications into customer capital expenditures, operatingexpenditures and overall completeness of a vendor's radio offerings.These engineering and systems design tradeoffs can result in what can begenerally characterized as overall radio size, weight, thermaldissipation, reliability, complexity, and cost.

Prior approaches to radios can omit custom tap points. A reason for thiscan be that an engineering organization has created a radio systemarchitecture over years, and adding custom tap points would require asignificant overhaul of this radio system architecture. That is, wherethere is an installed base on software and operational controlapproaches features exists, and this installed base does not include alevel of access via tap points, then a change to introduce tap pointscan disrupt this installed base of products.

Another reason can be that, prior approaches to radios can involve aradio developer selling a radio system to an expert customer, such as aTier 1 carrier that has its own engineering team that is capable ofperforming certain radio system functions (e.g., those that supportlong-term management and maintenance of a radio system via a view intomidpoints of the system) without the use of custom tap points. In anexample where there is not a legacy radio system architecture to bebuilt upon, and where an entity that uses the radio system has lessexpertise with radio systems than a Tier 1 carrier (e.g., a non-carrierbusiness, or a person), custom tap points can be implemented to solve aproblem of analyzing radio system performance by facilitating injectingand reading signals at specific points within a radio system.

As described herein, a signal injected into a custom tap point of aradio system can be time aligned with the radio system, and masking canbe applied to the injected signal to selectively inject the signal intothe radio system.

An ability to generate customized signal data and inject into a radio'ssignal chain can be tantamount to an ability to further capture andderive key performance data from radio sub-systems. According to thepresent techniques, and analogous to custom waveforms from a signalgenerator, a custom signal can be injected or added to live-air trafficsignals (which can sometimes be referred to as mission mode signals) tobecome a custom hybrid of live-air traffic signal data. Custom signals,or signals independent of live-air traffic signals (that is,non-live-air traffic signals, which can sometimes be referred to asnon-mission mode signals) can also be generated. Custom signal data can,in many instances, be statistically equivalent to live-air traffic data.In some examples according to the present techniques, live-air trafficdata can be used as if it were custom data.

An ability to read, record and recall data for further analysis canfacilitate a deeper understanding of system performance (among otherthings), and can be further used to determine improved performanceaspects of system operation, maintenance, and customer experience (amongother things).

The present techniques can be implemented to create and inject customwaveforms into custom tap points in a digital front end of a radio unit.In some examples, custom tap points are not part of a standard digitalfront end data path, and are added to support this injection.

In some examples, creation and injection of custom waveforms can happenin a down link path of a radio unit. In some examples, creation andinjection of custom waveforms can happen in an up link path of a radiounit. Signal injection can be derived from a radio unit-based source ina time domain.

Coverage for all antenna branches of a radio can be provided. Data canbe introduced to each antenna branch, and can be the same data for eachbranch, or different data for different branches. Data can be introducedto a down link signal path and/or an up link signal path.

In some examples, data can be injected at any tap point along a system'ssignal chain in a down link, feedback, or up link path. Data can passthrough one or multiple digital front end blocks. Data can pass to ananalog portion of a radio's signal chain. Multiple injection paths canexist where a multiplicity of signal data can be introduced at differenttap points, which can include different antenna branches,simultaneously.

Custom data (which can sometimes be referred to as a value, or a signalor a waveform when viewed over a time period) according to the presenttechniques can be originated in several ways, including the following. Amemory that is onboard to the radio can be configured to temporally playa suitable waveform or noise-like signal. A dynamic resource block(RB)/resource element (RE) allocation can be configured to, in someexamples generate between 1 and 4,096 (or other) inphase and quadrature(I+Q, or I/Q) 16 bit (signed) data pairs of arbitrary sub-carrier valuesfor a given desired modulation coding scheme (MCS). Such a dynamic RB/REallocation can be operated as a Moore machine or a Mealy machine.

In some examples, with regard to originating custom data and toanalyzing a radio via hardware acceleration, knowing the source signal(e.g., data) in advance can be used to determine performance based onthe injected signal. That is, there can be a case where input data isnot captured in the system, but is known to the system. In such a case,a derivation of performance based on the pre-selected captured data canbe compared in memory to the original data (rather than captured data),where the original data is determined based on a memory comparisonrather than a capture. This approach can save computing resourcesrelative to capturing the input data.

A look up table can be configured to store predetermined I/Q datavalues, which are each able to represent a component of a constellationof a given MCS level. Look up table data can be played in order, orrandomized to be playable in any order. In some examples, a look uptable can fulfill a given constellation/MCS symbol map and apredetermined complementary cumulative distribution function (CCDF). Asignal from a look up table can be a one-tone signal or a multi-tonesignal.

A pseudo-random look up table generator can operate in conjunction witha look up table. A pseudo-random look up table generator can comprise ablock that operates on the look up table's I/Q data and produces apseudo random symbol of data values of suitable random distribution.Values can be selected from the look up table in a random fashion tofulfill a symbol (e.g., a complete RB matrix) of signal data).

Regarding dimensioning, 1 I+Q data pair can be equivalent to 1 resourceelement/sub-carrier in a frequency domain. In an example, there can beup to 4,096 resource elements of I+Q, up to 16 bits (signed data pairs).In an example, data generated for a radio unit can support masking sothat all, or a subset, of the 0 to 4,095 resource elements available caneither be passed to, or removed from, a data stream via an AND/OR block.In some examples, a mask can be enabled or disabled, where a disabledmask is a pass-through state.

MCSes can be available as supported by radio requirements. Data can betriggered and time aligned with system timing on a symbol by symbolbasis. In some examples, data can be triggered and time aligned based onother relevant system time boundaries.

In some examples, data AND/OR blocks can be implemented for selecting asource of data. A distributed unit can provision one resource, or aplurality of resources, of signal data available to radio unit sourcedsignal data for injection of custom data. Data can be sourced purelyfrom a distributed unit live-air traffic u-plane path source (that is,the data can be live-air traffic data). Data can be sourced purely fromsources internal to a radio unit, and injected into the u-plane datapath (that is, the data can be non-live-air traffic data). These sourcescan include a memory, a dynamic RB/RE generator, a look up table, and apseudo-random look up table, with or without a mask enabled. Data can besourced from a combination of both sources for a distributed unit andradio unit u-plane (That is, the data can be a hybrid of live-airtraffic data and non-live-air traffic data).

In some examples, pure live-air traffic signal data, hybrid custom andlive-air traffic signal data, and full custom data can be generated onthe distributed unit alone. In some examples, a radio unit can passlive-air traffic data unmodified (e.g., pure live-air traffic data), canmanufacture a custom hybrid data of custom and live-air traffic data,and can provide full custom data. That is, in examples, data (be itpure, hybrid, or full-custom) can be solely originated by the RU, orsolely originated by the DU. And in some examples, a combination oflive-traffic data from a distributed unit and hybrid-custom data from aradio unit can be originated.

The present techniques can be implemented to facilitate custom signalgeneration handling and routing. Optional inverse Fast Fourier Transformcan be performed on a custom signal so that the custom signal can begenerated in a time domain. Cyclic prefix insertion can be optionallyperformed, as can gain control.

Time alignment can be performed on a custom signal, and can include fullsignal pre-conditioning in a time domain and a frequency domain.Hardware acceleration can be implemented for preconditioning in realtime based on down stream signal capture and post processing.

Custom signals can be dynamically controlled and used in conjunctionwith live-air signals. The present techniques can be implemented tocontrol which blocks see injected signals.

Example Architectures

FIG. 1 illustrates an example system architecture 100 for injecting asignal into a radio down link chain, and that can facilitate signalinjection at radio tap points in a time domain, in accordance with anembodiment of this disclosure.

System architecture 100 can function as a down link signal path ofradio. As depicted, system architecture 100 comprises custom signal datamemory, generation, masking, and buffer 102 (which can comprise acombination of some or all of a look up table, a pseudo-random look uptable generator, a generator, a memory, an OR gate to combine datasources, masking, and a buffer), time alignment 116, custom symbolresource blocks bands/resource elements (RBs/REs) 118, inverse FastFourier Transform (iFFT) 120 (which can also perform Δ gain, timealignment, and optional cyclic prefix (CP) insertion), RB/RE 122,iFFT/CP 124, digital front end (DFE) block 1 126, DFE block 2 128, crestfactor reduction (CFR) 130, digital pre-distortion (DPD) 132,delta-time-phase (ΔTΘ) 134, adaptation and correlation 136, feedbackreceiver analog-to-digital converter 138, transmitter digital to-analogconverter 140, power amplifier 144, signal coupler 146, tap point 148A,tap point 148B, tap point 148C, tap point 148D, tap point 148E, tappoint 148F, tap point 148G, tap point select 150, select 152, signaldata 154, and AND/OR 156.

Custom signal data memory, generation, masking, and buffer 102 cancreate a custom signal. This custom signal can then be selectivelyinjected at one or more of tap point 148A, tap point 148B, tap point148C, tap point 148D, tap point 148E, tap point 148F, and tap point 148Gby selecting a tap point with tap point select 150.

By selectively injecting a signal at a particular tap point, certainblocks of a down link chain can be avoided by the signal. This can beimplemented to, for example, selectively measure the performance of asub-portion of a radio.

Custom signal data memory, generation, masking, and buffer 102 can beused to originate the signal. Then, masking of custom signal datamemory, generation, masking, and buffer 102 can comprise ahardware-accelerated approach to shift data in frequency. That is, andby way of example, a custom signal can be created that comprisessubcarriers of different frequencies, where a component that createsthese symbols is turned on, and the data is streaming from a memory, alook up table, etc. In this example, masking can mask the subcarriers onthe fly at a rate of symbol by symbol, so that subcarriers can bequickly moved around, as opposed to recreating them.

A buffer of custom signal data memory, generation, masking, and buffer102 can ensure time alignment of the custom signal. The buffer canbuffer (or trigger or gate) the custom signal until determining anappropriate system time (based on time alignment 116) to release itforward in the signal chain.

Time alignment 116 can use system timing of a logic device to advance orslow gating of a data stream. In some examples, this can be an ON/OFF.On other examples, this can operate as a more complex timing/gatingpulse where data presence or absence can follow other system timingtriggers, such as time-division duplexing (TDD) DL/UL and guard periodtiming, power amplifier on or off (PA_ON/OFF), symbol start/stopmarkers, blanking, etc.

FIGS. 2A and 2B illustrate an example system architecture 200 forinjecting a signal into a radio down link chain, and that can facilitatesignal injection at radio tap points in a time domain, in accordancewith an embodiment of this disclosure.

Relative to system architecture 100 of FIG. 1 , system architecture 200can incorporate capture of a signal accessed via a tap point (capture242) and analysis of that captured signal (hardware accelerated signaldata pre-conditioning and memory 258).

System architecture 200 can function as a down link signal path ofradio. In addition to capture 242, and hardware accelerated signal datapre-conditioning and memory 258, as depicted, system architecture 200comprises custom signal data memory, generation, masking, and buffer202, time alignment 216, custom symbol RBs/REs 218, iFFT 220, RB/RE 222,iFFT/CP 224, DFE block 2 226, DFE block 2 228, CFR 230, DPD 232,delta-time-phase (ΔTΘ) 234, adaptation and correlation 236, feedbackreceiver analog-to-digital converter 238, transmitter digital to-analogconverter 240, power amplifier 244, signal coupler 246, tap point 248A,tap point 248B, tap point 248C, tap point 248D, tap point 248E, tappoint 248F, tap point 248G, tap point select 250, select 252, signaldata 254, and AND/OR 256.

These elements of system architecture 200 can be similar to customsignal data memory, generation, masking, and buffer 102, time alignment116, custom symbol RBs/REs 118, iFFT 120 (which can also perform Δ gain,time alignment, and optional cyclic prefix CP insertion), RB/RE 122,iFFT/CP 124, DFE block 1 126, DFE block 2 128, CFR 130, DPD 132,delta-time-phase (ΔTΘ) 134, adaptation and correlation 136, feedbackreceiver analog-to-digital converter 138, transmitter digital to-analogconverter 140, power amplifier 144, signal coupler 146, tap point 148A,tap point 148B, tap point 148C, tap point 148D, tap point 148E, tappoint 148F, tap point 148G, tap point select 150, select 152, signaldata 154, and AND/OR 156, respectively.

FIGS. 3A and 3B illustrate an example system architecture 300 forinjecting a signal into a radio up link chain, and that can facilitatesignal injection at radio tap points in a time domain, in accordancewith an embodiment of this disclosure. In some examples, a radio cancomprise part(s) of system architecture 200 of FIGS. 2A and 2B as a downlink chain, and part(s) of system architecture 300 as an up link chain.

As depicted, system architecture 300 comprises custom signal datamemory, generation, masking, and buffer 302 (which can be similar tocustom signal data memory, generation, masking, and buffer 202 of FIGS.2A and 2B), time alignment 316 (which can be similar to time alignment216), custom symbol RBs/REs 318A and custom symbol RBs/REs 318B (whichcan each be similar to an instance of custom symbol RBs/REs 218; in someexamples RBs/REs 318B data can be live-air up link signal data; in someexamples RBs/REs 318B data can be a version of RBs/REs 318A data afterpassing through up link digital front end blocks; in some examples,RBs/REs 318A data is the same as RBs/REs 318B data), iFFT 320 (which canbe similar to iFFT 220), RB/RE 322 (which can be similar to RB/RE 222),FFT/CP removal 324, DFE block N+1 326 (which can be similar to DFE block1 226), DFE block N 328 (which can be similar to DFE block 1 226), DFEblock 1 330 (which can be similar to DFE block 1 226), DFE block 0 332(which can be similar to DFE block 1 226), receiver analog-to-digitalconverter 334, storage 336, AND/OR 338, tap point selection 340, tappoint 348A (which can be similar to an instance of tap point 248A), tappoint 348B (which can be similar to an instance of tap point 248A), tappoint 348C (which can be similar to an instance of tap point 248A), tappoint 348D (which can be similar to an instance of tap point 248A), andtap point 348E (which can be similar to an instance of tap point 248A).

In system architecture 300, custom signal data memory, generation,masking, and buffer 302, time alignment 316, custom symbol RBs/REs 318A,and iFFT 320 can function together to create a custom signal (similar toin FIGS. 2A and 2B, with custom signal data memory, generation, masking,and buffer 202, time alignment 216, custom symbol RBs/REs, and iFFT220).

This custom signal can then be selectively injected at one or more oftap point 348A, tap point 348B, tap point 348C, tap point 348D, and tappoint 348E.

By selectively injecting a signal at a particular tap point, certainblocks of a down link chain can be avoided by the signal. This can beimplemented to, for example, selectively measure the performance of asub-portion of a radio.

FIGS. 4A and 4B illustrate illustrates an example system architecture400 for a radio unit, and that can facilitate signal injection at radiotap points in a time domain, in accordance with an embodiment of thisdisclosure. In some examples, system architecture 400 can comprise aradio unit that comprises part(s) of system architecture 200 of FIGS. 2Aand 2B as a down link chain, and part(s) of system architecture 300 ofFIGS. 3A and 3B as an up link chain.

As depicted, system architecture 400 comprises distributed unit (DU)control user synchronization management (CUSM) plane intermediatefrequency (I/F) 402, live-air traffic signals from DU 404, live-airtraffic signals to DU 406, optional iFFT and CP 408, iFFT and CP 410, RUoriginated custom non-live-air traffic signals 412, DL DFE chain 414,radio optimization controller 416, optional FFT and optional CP removal418, FFT and CP removal 420, waveform/RB/RE signal data 422A andwaveform/RB/RE signal data 422B, Rx 424, UL DFE chain 426, measurementblock 428, transceiver 430, transmission (Tx) blocks 432, feedbackreceiver (FBRx) blocks 434, receiver (Rx) blocks 436, Tx or transceiver(TRx) port 438, and antenna calibration (AntCal) and built-in self-test(BIST) calibration port 440.

DL DFE chain 414 can include CFR and DPD. Measurement block 428 cancomprise signal (data) generation, power (data) detectors, statisticalcounters, injection tap points, capture tap points, and/or hardwareaccelerated signal data pre-selection.

Tx blocks 432 can include Tx low, pre-drivers and drivers, poweramplifier (PA) final stage), signal feedback, and non-live-air trafficalternate analog path options. FBRx blocks 434 can include a live-airtraffic FBRx path, voltage standing wave ratio (VSWR) mode switching,and non-live-air traffic alternate analog path options. Rx blocks 436can include a live-air traffic low noise amplifier (LNA) path, VSWRswitching, and non-live-air traffic analog path options. RU 442 caninclude a separate port for the case of frequency-division duplexing(FDD) radio architectures.

These above components of system architecture 400 can be part of radiounit (RU) 442. System architecture 400 also comprises distributed unit(DU) 444, scheduler 446, custom symbol resource blocks/resource elements(RBs/REs) 448, custom signal data memory, generation, masking, andbuffer 450, time alignment 452, hardware accelerated signal datapre-conditioning and memory 454, analysis and fault detection 456, radiooptimization control and actuation 458, and storage 460.

In system architecture 400, custom signals can be generated and theninjected into tap points in either a DL chain or an UL chain. Customsignals can be generated at RU originated custom non-live-air trafficsignals 412, and in some examples, combined with live-air trafficsignals from DU 404. The resulting signal can be injected into variousparts of DL DFE chain 414 (via optional iFFT/optional CP 408) or UL DFEchain 426 via tap points of measurement block 428.

FIGS. 5A, 5B, 5C, and 5D illustrate an example system architecture 500for a radio system, and that can facilitate signal injection at radiotap points in a time domain, in accordance with an embodiment of thisdisclosure. In some examples, system architecture can comprise a radiosystem that can comprise part(s) of system architecture 100 of FIG. 1 ,system architecture 200 of FIGS. 2A and 2B, system architecture 300 ofFIGS. 3A and 3B, and/or system architecture 400 of FIGS. 4A and 4B.

As depicted, system architecture 500 comprises custom signal datamemory, generation, masking, and buffer 502A and custom signal datamemory, generation, masking, and buffer 502B; time alignment 504A andtime alignment 504B; custom symbol RBs/REs 506; from timing systemsource 508; distributed unit 510; hardware accelerated signal data,pre-conditioning and memory 512A, hardware accelerated signal data,pre-conditioning and memory 512B, and hardware accelerated signal data,pre-conditioning and memory 512C; analysis 514A, analysis 514B, andanalysis 514C; control and activation 516A, control and activation 516B,and control and activation 516C; data storage 518; RU 520; custom symbolRBs/REs 522; inverse Fast Fourier Transform (iFFT) 524 (which can alsoperform Δ gain, cyclic prefix insertion, and time alignment); cavityfilter 526; radiofrequency (RF) front end (RFFE) 528 (which can includelow noise amplifiers (LNAs), switches, attenuators, filters, PAs,couplers, and power supplies); transceiver 530 (which can include Tx,FBRx, and Rx); digital front end 532 (which can include filters, CFR,DPD, a digital to analog converter (DACs), an analog to digitalconverter (ADC), a digital down converters (DDC), a digital up converter(DUC), and iFFT/FFT, CP, and muxing); time domain path 534 (which canbypass CP injection and iFFT); frequency domain path 536; time domainpath 538 (which can bypass CP removal and FFT); CP removal or bypass540; FFT 542; temporal frequency domain (FD) data stream 544; temporaltime domain (TD) data stream 546; DU C/M-plane 548A and DU C/M-plane548B; control system aggregation 550A and control system aggregation550B; analysis database 552A and analysis database 552B; and radioresources 554.

Hardware accelerated signal data pre-conditioning and memory 512A, andhardware accelerated signal data pre-conditioning and memory 512C canperform frequency domain signal data detection.

Hardware accelerated signal data pre-conditioning and memory 512B canperform time domain signal data detection.

Custom signal data memory, generation, masking, and buffer 502A andcustom signal data memory, generation, masking, and buffer 502B canperform signal generation at a distributed unit or a radio unit,respectively. They can perform local synchronized custom and live-airdata stimulus with known characteristics. In some examples, they canoperate in a frequency domain.

Analysis 514A, analysis 514B, and analysis 514C can perform signalcapture data analysis. In some examples, they can implement artificialintelligence/machine learning (AI/ML) with training (such as live andstored real-time data, and statistical data). They can provide an outputof a response to actuators to change operational parameters of a radiosystem.

Control and activation 516A, control and activation 516B, and controland activation 516C can take inputs that augment information availableto an AI/ML component and output an affect to actuators of the radiosystem to change operational parameters.

In some examples, respective outputs of control and activation 516B andcontrol and activation 516C can be aggregated to affect change on aradio and radio performance.

In system architecture 500, custom signals can be generated and theninjected into tap points in either a DU or an RU. Regarding the DU, thecustom signals can be originated from custom signal data memory,generation, masking, and buffer 502A (which can be similar to customsignal data memory, generation, masking, and buffer 202 of FIGS. 2A and2B, in conjunction with time alignment 504A). Regarding the RU, thecustom signals can be originated from custom signal data memory,generation, masking, and buffer 502B (which can comprise a combinationof components similar to custom signal data memory, generation, masking,and buffer 302 of FIGS. 3A and 3B, in conjunction with time alignment504B).

FIG. 6 illustrates an example system architecture 600 that canfacilitate signal injection at radio tap points in a time domain, inaccordance with an embodiment of this disclosure. In some examples,part(s) of system architecture 600 can be used to implement part(s) ofsystem architecture 100 of FIG. 1 , system architecture 200 of FIGS. 2Aand 2B, system architecture 300 of FIGS. 3A and 3B, system architecture400 of FIGS. 4A and 4B, and/or system architecture 500 of FIGS. 5A, 5B,5C, and 5D.

System architecture 600 comprises radio unit 602, first component thatis configured to originate the first custom signal 604, and secondcomponent that is configured to select a first tap point of the group oftap points, and inject the first custom signal into the first tap point606. In turn, radio unit 606 comprises digital front end 608, whichitself comprises tap points 610.

Radio unit 602 can be similar to system architecture 400 of FIGS. 4A and4B. First component that is configured to originate the first customsignal 604 can be similar to custom signal data memory, generation,masking, and buffer 202 of FIGS. 2A and 2B. First component that isconfigured to originate the first custom signal 604 originate the signalfrom one, or a combination of multiple, of components of custom signaldata memory, generation, masking, and buffer 202, such as a memory, alook up table, a pseudo-random look up table generator, or a generator.

Using the example of FIGS. 2A and 2B, second component that isconfigured to select a first tap point of the group of tap points, andinject the first custom signal into the first tap point 606 can besimilar to tap point select 250, and select a first tap point from amongtap point 248A, tap point 248B, tap point 248C, tap point 248D, tappoint 248E, tap point 248F, and tap point 248G, and inject the customsignal into this selected first tap point.

In some examples, the first tap point is positioned in a down link pathof the radio unit. This can be, for example, tap point 248A of FIGS. 2Aand 2B. In some examples, the first tap point is positioned in an uplink path of the radio unit. This can be, for example, tap point 348B ofFIGS. 3A and 3B. In some examples, the first tap point is positioned ina feedback path of the radio unit. This can be, for example, tap point248E of FIGS. 2A and 2B.

In some examples, the second component is configured to inject the firstcustom signal into the first tap point in a time domain portion of theradio unit. This can be, for example, tap point 248A, tap point 248B,tap point 248C, tap point 248D, tap point 248E, and tap point 248F ofFIGS. 2A and 2B. Each of these tap points is positioned in a time domainportion of a radio unit, as opposed to a frequency domain portion of theradio unit.

FIG. 7 illustrates another example system architecture 700 that canfacilitate signal injection at radio tap points in a time domain, inaccordance with an embodiment of this disclosure. In some examples,part(s) of system architecture 700 can be used to implement part(s) ofsystem architecture 100 of FIG. 1 , FIGS. 2A and 2B, system architecture300 of FIGS. 3A and 3B, system architecture 400 of FIGS. 4A and 4B,and/or system architecture 500 of FIGS. 5A, 5B, 5C, and 5D.

System architecture comprises radio unit 702 (which can be similar toradio unit 602 of FIG. 6 ), first component that is configured tooriginate the first custom signal 704 (which can be similar to firstcomponent that is configured to originate the first custom signal 604),second component that is configured to select a first tap point of thegroup of tap points, and inject the first custom signal into the firsttap point 706 (which can be similar to second component that isconfigured to select a first tap point of the group of tap points, andinject the first custom signal into the first tap point 606), digitalfront end 708 (which can be similar to digital front end 608), tappoints 710 (which can be similar to tap points 610), third componentthat is configured to read a second signal from the radio unit 712, andfourth component that is configured to determine a performance metric ofa sub-system of the radio unit based on a comparison of the first customsignal and the second signal 714.

Using the example of FIGS. 2A and 2B, second component that isconfigured to select a first tap point of the group of tap points, andinject the first custom signal into the first tap point 706 can inject asignal at one tap point, and third component that is configured to reada second signal from the radio unit 712 can read the signal at anothertap point. For example, second component that is configured to select afirst tap point of the group of tap points, and inject the first customsignal into the first tap point 706 can inject a signal at tap point248A of FIGS. 2A and 2B, and third component that is configured to reada second signal from the radio unit 712 can read the signal at tap point248B, similar to tap point select 250.

Then, fourth component that is configured to determine a performancemetric of a sub-system of the radio unit based on a comparison of thefirst custom signal and the second signal 714 can use the differencebetween the signal injected at tap point 248A and the correspondingsignal read at tap point 248B to determine performance of a portion of aradio located between those two points. In the example of FIGS. 2A and2B, this is DFE block 2 226.

FIG. 8 illustrates another example system architecture 800 that canfacilitate signal injection at radio tap points in a time domain, inaccordance with an embodiment of this disclosure. In some examples,part(s) of system architecture 800 can be used to implement part(s) ofsystem architecture 100 of FIG. 1 , FIGS. 2A and 2B, system architecture300 of FIGS. 3A and 3B, system architecture 400 of FIGS. 4A and 4B,and/or system architecture 500 of FIGS. 5A, 5B, 5C, and 5D.

System architecture comprises radio unit 802 (which can be similar toradio unit 602 of FIG. 6 ), first component that is configured tooriginate the first custom signal 804 (which can be similar to firstcomponent that is configured to originate the first custom signal 604),second component that is configured to select a first tap point of thegroup of tap points, and inject the first custom signal into the firsttap point 806 (which can be similar to second component that isconfigured to select a first tap point of the group of tap points, andinject the first custom signal into the first tap point 606), digitalfront end 808 (which can be similar to digital front end 608), tappoints 810 (which can be similar to tap points 610), first antennabranch 816 (comprising tap point 820), and second antenna branch 818(comprising tap point 822).

Each of tap point 820 and tap point 822 can be similar to an instance oftap point 248A of FIGS. 2A and 2B. In system architecture 800, tap point820 and tap point 822 are positioned in different antenna branches(where system architecture 800 comprises multiple antenna branches). Tappoint 820 is positioned in first antenna branch 816, and tap point 822is positioned in second antenna branch 818.

In some examples, the first tap point corresponds to the first antennabranch, and wherein the second component is configured to inject asecond custom signal into the second antenna branch. That is, multipledifferent signals can be injected into the respective tap points ofdifferent antennas. In other examples, the same signal can be injectedinto the respective tap points of different antennas.

In some examples, the first custom signal differs from the second customsignal, and the second component is configured to inject the firstcustom signal into the first tap point concurrently with injecting thesecond custom signal into the second antenna branch. That is, theinjection of multiple custom signals can be performed simultaneously, sothat system architecture 800 receives multiple custom signals at thesame time.

FIG. 9 illustrates another example system architecture 900 that canfacilitate signal injection at radio tap points in a time domain, inaccordance with an embodiment of this disclosure. In some examples,part(s) of system architecture 900 can be used to implement part(s) ofsystem architecture 100 of FIG. 1 , FIGS. 2A and 2B, system architecture300 of FIGS. 3A and 3B, system architecture 400 of FIGS. 4A and 4B,and/or system architecture 500 of FIGS. 5A, 5B, 5C, and 5D.

System architecture 900 comprises first component that is configured tooriginate a first custom signal 902, second component that is configuredto select a first tap point of a group of tap points of a digital frontend of a radio unit 904, and third component that is configured toinject the first custom signal into the first tap point 906.

In some examples, first component that is configured to originate afirst custom signal 902 can be similar to first component that isconfigured to originate the first custom signal 604 of FIG. 6 ; secondcomponent that is configured to select a first tap point of a group oftap points of a digital front end of a radio unit 904 can be similar toa portion of second component that is configured to select a first tappoint of the group of tap points, and inject the first custom signalinto the first tap point 606 that selects a tap point; and thirdcomponent that is configured to inject the first custom signal into thefirst tap point 906 can be similar to a portion of second component thatis configured to select a first tap point of the group of tap points,and inject the first custom signal into the first tap point 606 thatinjects a signal into a tap point.

In some examples, the first custom signal in system architecture 900bypasses a block of the radio unit that is configured to translatefrequency domain data into time domain data and insert a cyclic prefixwhen injected into the first tap point. That is, using the example ofFIGS. 2A and 2B, injected data can bypass iFFT/CP 224 and be injected attap point 248A.

In some examples, the first custom signal comprises live-air trafficdata that is sourced from a distributed unit of a radio, wherein theradio comprises the radio unit. In some examples, the first customsignal comprises a combination of live-air traffic data that is sourcedfrom a distributed unit of a radio, and custom data, wherein the radiocomprises the radio unit. That is, data can be a combination of missiondata sourced from a distributed unit and non-live-air traffic sources,solely live-air traffic data, or solely non-live-air traffic data.

FIG. 10 illustrates another example system architecture that canfacilitate signal injection at radio tap points in a time domain, inaccordance with an embodiment of this disclosure. In some examples,part(s) of system architecture 1000 can be used to implement part(s) ofsystem architecture 100 of FIG. 1 , FIGS. 2A and 2B, system architecture300 of FIGS. 3A and 3B, system architecture 400 of FIGS. 4A and 4B,and/or system architecture 500 of FIGS. 5A, 5B, 5C, and 5D.

System architecture 1000 comprises first component that is configured tooriginate a first custom signal 1002 (which can be similar to firstcomponent that is configured to originate a first custom signal 902 ofFIG. 9 ), second component that is configured to select a first tappoint of a group of tap points of a digital front end of a radio unit1004 (which can be similar to second component that is configured toselect a first tap point of a group of tap points of a digital front endof a radio unit 904), third component that is configured to inject thefirst custom signal into the first tap point 1006 (which can be similarto third component that is configured to inject the first custom signalinto the first tap point 906), memory that stores signal data 1008,generator that is configured to generate first in-phase, quadraturesub-carrier values 1010, look up table 1012, and pseudo-random look uptable generator 1014.

In some examples, memory that stores signal data 1008, generator that isconfigured to generate first in-phase, quadrature sub-carrier values1010, look up table that stores predetermined second in-phase,quadrature sub-carrier values 1012, and pseudo-random look up tablegenerator that is configured to operate on the predetermined secondin-phase, quadrature sub-carrier values to produce a pseudo-randomsymbol of data values 1014 can be similar to components of custom signaldata memory, generation, masking, and buffer 102 of FIG. 1 .

FIG. 11 illustrates another example system architecture that canfacilitate signal injection at radio tap points in a time domain, inaccordance with an embodiment of this disclosure. In some examples,part(s) of system architecture 1100 can be used to implement part(s) ofsystem architecture 100 of FIG. 1 , FIGS. 2A and 2B, system architecture300 of FIGS. 3A and 3B, system architecture 400 of FIGS. 4A and 4B,and/or system architecture 500 of FIGS. 5A, 5B, 5C, and 5D.

System architecture 1100 comprises first component that is configured tooriginate a first custom signal 1102 (which can be similar to firstcomponent that is configured to originate a first custom signal 902 ofFIG. 9 ), second component that is configured to select a first tappoint of a group of tap points of a digital front end of a radio unit1104 (which can be similar to second component that is configured toselect a first tap point of a group of tap points of a digital front endof a radio unit 904), third component that is configured to inject thefirst custom signal into the first tap point 1106 (which can be similarto third component that is configured to inject the first custom signalinto the first tap point 906), and fourth component that is configuredto align the first custom signal on a time boundary of the radio unit1116.

In some examples, fourth component that is configured to align the firstcustom signal on a time boundary of the radio unit 1116 can be similarto iFFT 220 of FIGS. 2A and 2B. That is, in the example of FIGS. 2A and2B, time alignment 216 can comprise a block that derives a signal usedby a mechanism that aligns data, and this mechanism that aligns data canbe part of iFFT 220.

FIG. 12 illustrates another example system architecture that canfacilitate signal injection at radio tap points in a time domain, inaccordance with an embodiment of this disclosure. In some examples,part(s) of system architecture 1200 can be used to implement part(s) ofsystem architecture 200 of FIGS. 2A and 2B, system architecture 300 ofFIGS. 3A and 3B, system architecture 400 of FIGS. 4A and 4B, and/orsystem architecture 500 of FIGS. 5A, 5B, 5C, and 5D.

System architecture 1200 comprises first component that is configured tooriginate a first custom signal 1202 (which can be similar to firstcomponent that is configured to originate a first custom signal 902 ofFIG. 9 ), second component that is configured to select a first tappoint of a group of tap points of a digital front end of a radio unit1204 (which can be similar to second component that is configured toselect a first tap point of a group of tap points of a digital front endof a radio unit 904), third component that is configured to inject thefirst custom signal into the first tap point 1206 (which can be similarto third component that is configured to inject the first custom signalinto the first tap point 906), and fourth component that is configuredadjust a gain of the first custom signal before the second componentinjects the first custom signal into the first tap point 1218.

In some examples, fourth component that is configured adjust a gain ofthe first custom signal before the second component injects the firstcustom signal into the first tap point 1218 can be similar to iFFT 220of FIGS. 2A and 2B.

Example Process Flow

FIG. 13 illustrates an example process flow 1300 that can facilitatesignal injection at radio tap points in a time domain, in accordancewith an embodiment of this disclosure. In some examples, one or moreembodiments of process flow 1300 can be implemented by systemarchitecture 200 of FIGS. 2A and 2B.

It can be appreciated that the operating procedures of process flow 1300are example operating procedures, and that there can be embodiments thatimplement more or fewer operating procedures than are depicted, or thatimplement the depicted operating procedures in a different order than asdepicted.

Process flow 1300 begins with 1302, and moves to operation 1304.

Operation 1304 depicts identifying, by a system comprising a processor,a group of tap points in a digital front end of a radio unit, whereinthe group of tap points are configured to receive a first custom signal.In some examples, these tap points can comprise tap point 248A, tappoint 248B, tap point 248C, tap point 248D, tap point 248E, and tappoint 248F of FIGS. 2A and 2B. Identifying these tap points can comprisestoring an indication of a location of these tap points within a radioin a computer memory, or otherwise determining (or maintaininginformation regarding) which part of a radio system each tap point islocated in.

After operation 1304, process flow 1300 moves to operation 1306.

Operation 1306 depicts originating the first custom signal. This cancomprise originating a signal from custom signal data memory,generation, masking, and buffer 202 FIGS. 2A and 2B.

After operation 1306, process flow 1300 moves to operation 1308.

Operation 1308 depicts selecting a first tap point from the group of tappoints. Using the example of FIGS. 2A and 2B (with tap point 248A, tappoint 248B, tap point 248C, tap point 248D, tap point 248E, and tappoint 248F), this can comprise determining which of these tap points thecustom signal of operation 1306 will be injected into.

After operation 1308, process flow 1300 moves to operation 1310.

Operation 1310 depicts injecting, by the system, the first custom signalinto the first tap point to produce an injected first custom signal.This can comprise injecting the first custom signal that is originatedin operation 1306 into the first tap point that is selected in operation1308, and can be performed by a component similar to tap point select250 of FIGS. 2A and 2B, or tap point selection 340 of FIGS. 3A and 3B.

In some examples, the first custom signal passes through one digitalfront end block of the radio unit when injected into the first tappoint. In some examples, the first custom signal passes through multipledigital front end blocks of the radio unit when injected into the firsttap point. That is, when injected into a specific tap point, a customsignal can then pass through one, or multiple, digital front end blocks.In some examples, the first custom signal passes to an analog portion ofa signal chain of the radio unit when injected into the first tap point.That is, injected data can pass to an analog portion of a radio's signalchain.

After operation 1310, process flow 1300 moves to operation 1312.

Operation 1312 depicts selectively masking a portion of the injectedfirst custom signal to produce a masked first custom signal. In someexamples, operation 1312 can be implemented by a masking component ofcustom signal data memory, generation, masking, and buffer 202 of FIGS.2A and 2B.

After operation 1312, process flow 1300 moves to operation 1314.

Operation 1314 depicts time aligning the masked first custom signal witha time of the radio unit. In some examples, operation 1314 can beimplemented by time alignment 216 of FIGS. 2A and 2B. In some examples,operation 1314 comprises reading a second signal from the radio unit(which can be performed in a manner similar to third component that isconfigured to read a second signal from the radio unit 712 of FIG. 7 ),and determining a performance metric of a sub-system of the radio unitbased on a comparison of the first custom signal and the second signal(which can be performed in a manner similar to fourth component that isconfigured to determine a performance metric of a sub-system of theradio unit based on a comparison of the first custom signal and thesecond signal 714).

After operation 1314, process flow 1300 moves to 1316, where processflow 1300 ends.

CONCLUSION

As it employed in the subject specification, the term “processor” canrefer to substantially any computing processing unit or devicecomprising, but not limited to comprising, single-core processors;single-processors with software multithread execution capability;multi-core processors; multi-core processors with software multithreadexecution capability; multi-core processors with hardware multithreadtechnology; parallel platforms; and parallel platforms with distributedshared memory in a single machine or multiple machines. Additionally, aprocessor can refer to an integrated circuit, a state machine, anapplication specific integrated circuit (ASIC), a digital signalprocessor (DSP), a programmable gate array (PGA) including a fieldprogrammable gate array (FPGA), a programmable logic controller (PLC), acomplex programmable logic device (CPLD), a discrete gate or transistorlogic, discrete hardware components, or any combination thereof designedto perform the functions described herein. Processors can exploitnano-scale architectures such as, but not limited to, molecular andquantum-dot based transistors, switches and gates, in order to optimizespace usage or enhance performance of user equipment. A processor mayalso be implemented as a combination of computing processing units. Oneor more processors can be utilized in supporting a virtualized computingenvironment. The virtualized computing environment may support one ormore virtual machines representing computers, servers, or othercomputing devices. In such virtualized virtual machines, components suchas processors and storage devices may be virtualized or logicallyrepresented. For instance, when a processor executes instructions toperform “operations”, this could include the processor performing theoperations directly and/or facilitating, directing, or cooperating withanother device or component to perform the operations.

In the subject specification, terms such as “datastore,” data storage,”“database,” “cache,” and substantially any other information storagecomponent relevant to operation and functionality of a component, referto “memory components,” or entities embodied in a “memory” or componentscomprising the memory. It will be appreciated that the memorycomponents, or computer-readable storage media, described herein can beeither volatile memory or nonvolatile storage, or can include bothvolatile and nonvolatile storage. By way of illustration, and notlimitation, nonvolatile storage can include ROM, programmable ROM(PROM), EPROM, EEPROM, or flash memory. Volatile memory can include RAM,which acts as external cache memory. By way of illustration and notlimitation, RAM can be available in many forms such as synchronous RAM(SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rateSDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), Synchlink DRAM (SLDRAM), anddirect Rambus RAM (DRRAM). Additionally, the disclosed memory componentsof systems or methods herein are intended to comprise, without beinglimited to comprising, these and any other suitable types of memory.

The illustrated embodiments of the disclosure can be practiced indistributed computing environments where certain tasks are performed byremote processing devices that are linked through a communicationsnetwork. In a distributed computing environment, program modules can belocated in both local and remote memory storage devices.

The systems and processes described above can be embodied withinhardware, such as a single integrated circuit (IC) chip, multiple ICs,an ASIC, or the like. Further, the order in which some or all of theprocess blocks appear in each process should not be deemed limiting.Rather, it should be understood that some of the process blocks can beexecuted in a variety of orders that are not all of which may beexplicitly illustrated herein.

As used in this application, the terms “component,” “module,” “system,”“interface,” “cluster,” “server,” “node,” or the like are generallyintended to refer to a computer-related entity, either hardware, acombination of hardware and software, software, or software in executionor an entity related to an operational machine with one or more specificfunctionalities. For example, a component can be, but is not limited tobeing, a process running on a processor, a processor, an object, anexecutable, a thread of execution, computer-executable instruction(s), aprogram, and/or a computer. By way of illustration, both an applicationrunning on a controller and the controller can be a component. One ormore components may reside within a process and/or thread of executionand a component may be localized on one computer and/or distributedbetween two or more computers. As another example, an interface caninclude input/output (I/O) components as well as associated processor,application, and/or application programming interface (API) components.

Further, the various embodiments can be implemented as a method,apparatus, or article of manufacture using standard programming and/orengineering techniques to produce software, firmware, hardware, or anycombination thereof to control a computer to implement one or moreembodiments of the disclosed subject matter. An article of manufacturecan encompass a computer program accessible from any computer-readabledevice or computer-readable storage/communications media. For example,computer readable storage media can include but are not limited tomagnetic storage devices (e.g., hard disk, floppy disk, magnetic strips. . . ), optical discs (e.g., CD, DVD . . . ), smart cards, and flashmemory devices (e.g., card, stick, key drive . . . ). Of course, thoseskilled in the art will recognize many modifications can be made to thisconfiguration without departing from the scope or spirit of the variousembodiments.

In addition, the word “example” or “exemplary” is used herein to meanserving as an example, instance, or illustration. Any embodiment ordesign described herein as “exemplary” is not necessarily to beconstrued as preferred or advantageous over other embodiments ordesigns. Rather, use of the word exemplary is intended to presentconcepts in a concrete fashion. As used in this application, the term“or” is intended to mean an inclusive “or” rather than an exclusive“or.” That is, unless specified otherwise, or clear from context, “Xemploys A or B” is intended to mean any of the natural inclusivepermutations. That is, if X employs A; X employs B; or X employs both Aand B, then “X employs A or B” is satisfied under any of the foregoinginstances. In addition, the articles “a” and “an” as used in thisapplication and the appended claims should generally be construed tomean “one or more” unless specified otherwise or clear from context tobe directed to a singular form.

What has been described above includes examples of the presentspecification. It is, of course, not possible to describe everyconceivable combination of components or methods for purposes ofdescribing the present specification, but one of ordinary skill in theart may recognize that many further combinations and permutations of thepresent specification are possible. Accordingly, the presentspecification is intended to embrace all such alterations, modificationsand variations that fall within the spirit and scope of the appendedclaims. Furthermore, to the extent that the term “includes” is used ineither the detailed description or the claims, such term is intended tobe inclusive in a manner similar to the term “comprising” as“comprising” is interpreted when employed as a transitional word in aclaim.

What is claimed is:
 1. A system, comprising: a radio unit comprising adigital front end, wherein the digital front end comprises a group oftap points that are configured to receive a first custom signal; a firstcomponent that is configured to originate the first custom signal; and asecond component that is configured to select a first tap point of thegroup of tap points, and inject the first custom signal into the firsttap point, wherein the first tap point is configured to selectively maska portion of the first custom signal, and wherein the first tap point isconfigured to align a timing of the first custom signal with a systemtime of the radio unit.
 2. The system of claim 1, further comprising: athird component that is configured to read a second signal from theradio unit, wherein the second signal is generated based on the firstcustom signal; and a fourth component that is configured to determine aperformance metric of a sub-system of the radio unit based on acomparison of the first custom signal and the second signal, wherein thefirst tap point corresponds to the sub-system.
 3. The system of claim 1,wherein the first tap point is positioned in a down link path of theradio unit.
 4. The system of claim 1, wherein the first tap point ispositioned in an up link path of the radio unit.
 5. The system of claim1, wherein the first tap point is positioned in a feedback path of theradio unit.
 6. The system of claim 1, wherein the second component isconfigured to inject the first custom signal into the first tap point ina time domain portion of the radio unit.
 7. The system of claim 1,further comprising: a first antenna branch of the radio unit, and asecond antenna branch of the radio unit; and wherein the group of tappoints comprises at least one tap point that corresponds to the firstantenna branch, and at least one tap point that corresponds to thesecond antenna branch.
 8. The system of claim 7, wherein the first tappoint corresponds to the first antenna branch, and wherein the secondcomponent is configured to inject a second custom signal into the secondantenna branch.
 9. The system of claim 8, wherein the first customsignal differs from the second custom signal, and wherein the secondcomponent is configured to inject the first custom signal into the firsttap point concurrently with injecting the second custom signal into thesecond antenna branch.
 10. A method, comprising: identifying, by asystem comprising a processor, a group of tap points in a digital frontend of a radio unit, wherein the group of tap points are configured toreceive a first custom signal; originating, by the system, the firstcustom signal; selecting, by the system, a first tap point from thegroup of tap points; injecting, by the system, the first custom signalinto the first tap point to produce an injected first custom signal;selectively masking, by the system, a portion of the injected firstcustom signal to produce a masked first custom signal; and timealigning, by the system, the masked first custom signal with a time ofthe radio unit.
 11. The method of claim 10, wherein the first customsignal passes through one digital front end block of the radio unit wheninjected into the first tap point.
 12. The method of claim 10, whereinthe first custom signal passes through multiple digital front end blocksof the radio unit when injected into the first tap point.
 13. The methodof claim 10, wherein the first custom signal passes to an analog portionof a signal chain of the radio unit when injected into the first tappoint.
 14. An apparatus, comprising: a first component that isconfigured to originate a first custom signal; a second component thatis configured to select a first tap point of a group of tap points of adigital front end of a radio unit; and a third component that isconfigured to inject the first custom signal into the first tap point.15. The apparatus of claim 14, wherein the first component that isconfigured to originate the first custom signal is configured to selectthe first custom signal from one or more of: a memory that stores signaldata; a generator that is configured to generate first in-phase,quadrature sub-carrier values; a look up table that stores predeterminedsecond in-phase, quadrature sub-carrier values; and a pseudo-random lookup table generator that is configured to operate on the predeterminedsecond in-phase, quadrature sub-carrier values to produce apseudo-random symbol of data values.
 16. The apparatus of claim 14,wherein the first custom signal bypasses a block of the radio unit thatis configured to translate frequency domain data into time domain dataand insert a cyclic prefix when injected into the first tap point. 17.The apparatus of claim 14, further comprising: a fourth component thatis configured to align the first custom signal on a time boundary of theradio unit.
 18. The apparatus of claim 14, further comprising: a fourthcomponent that is configured adjust a gain of the first custom signalbefore the second component injects the first custom signal into thefirst tap point.
 19. The apparatus of claim 14, wherein the first customsignal comprises live-air traffic data that is sourced from adistributed unit of a radio, wherein the radio comprises the radio unit.20. The apparatus of claim 14, wherein the first custom signal comprisesa combination of live-air traffic data that is sourced from adistributed unit of a radio, and custom data, wherein the radiocomprises the radio unit.